Urological resectoscope comprising a contacting device

ABSTRACT

The invention relates to a urological resectoscope having an axially extending shaft tube, the proximal end thereof being fixed to a main body. A sliding body is proximally positioned in relation to the main body, and can slide in a parallel manner in relation to the axis thereof. Said sliding body comprises a receiver, a fixing device and a contacting device. An electrode which can be subjected to a high frequency, comprising an electrode carrier having one external, insulated conductive wire, can be positioned in the resectoscope in such a way that it can axially slide beyond the distal end of the shaft tube. In the assembly position, said electrode carrier extends through the shaft tube and the main body into the receiver, and can be fixed thereto by means of the fixing device and contacted therein by means of the contacting device. The inventive resectoscope is characterized in that the contacting device comprises an opening of the sliding body, said opening completely cutting through in a transversal direction in relation to the receiver, and extending perpendicularly in relation thereto, to a depth on the other side thereof. In the contacted state, the contacting device further comprises a clamping connector which is designed for pivotable clamping on a contact section of the electrode carrier.

[0001] The present invention relates to a resectoscope of the kinddefined in the preamble of claim 1.

[0002] Resectoscopes of that kind are intended foremost for prostateresection but, depending on particular design, optionally also may beused for other surgical applications. The term “resectoscope” usedherein denotes endoscopic instruments wherein an optics and an electrodesupport fitted with a distal electrode are configured in a stem tube,said electrode support with electrode being supported therein in axiallydisplaceable manner and being affixed by its proximal end to a slideblock of the resectoscope and being in electrical contact, said slideblock being manually displaceable in the axial direction when a grip isactuated in order to axially displace the electrode.

[0003] In prostate resection, the resectoscope is advanced by means ofthe distal end of the stem tube through the urethra into the inside ofthe prostate. When the electrode is loaded with hf, it can be advancedand retracted by means of said manual displacement of the slide block,to which it is proximally affixed, for the purpose of cutting tissue. Ingeneral the electrode assumes the shape of a wire loop to resect tissuesnippets. However the electrode also may assume other geometries, forinstance being a button electrode, a roller electrode, a knife electrodeor the like, in order to be used for different applications such ascoagulation, cutting and the like.

[0004] Problems are encountered in this regard in setting up the properelectric contact between the conductor wire applying a current to theelectrode and its contact zone in the slide block. The electric contactat the slide block must be set up to an extension cable running to aseparate hf generator.

[0005] In older designs, said electrical contact was set up by means ofa clamping screw and simultaneously mechanical affixation of theelectrode support was reliably assured in the slide block. Once saidcontact site charred, however, the entire slide block requiredreplacement.

[0006] A design of that kind is known from each FIG. 3 of the U.S. Pat.No. 4,917,621 and U.S. Pat. No. 4,919,131. Therein the slide block isfitted with a continuous clearance receiving the plug of the extensioncable that shall make electrical contact with the electrode support'scontact zone which is freely accessible in said clearance. A clampingelement acting on an affixation zone of the electrode support isconfigured distally from said clearance.

[0007] This design offers the advantage of separately mechanicallyaffixing the electrode support and the clamping element on the slideblock, as a result of which it is possible to first check this slideblock's appropriate mechanical operation. Thereupon contact may beimplemented with the plug. If the contact site should char, only theelectrode support and the cable together with the plug need be changed.The clamping element and the slide block on the other hand remain intactbecause the clamping element is separate.

[0008] This design of the known species however incurs the drawback of arigorous plug guidance within the said clearance, entailing apredetermined location on the cable issuing from the plug. This featureis a drawback as regards resectoscopes which, during surgery, forinstance in the prostate, must be continuously rotated in order to havethe electrode cut at different angles. This desideratum is impeded bythe fixed angular position of the hf cable issuing from the hf cable.

[0009] The objective of the present invention is to create aresectoscope of the above kind having improved properties regarding theexit of the hf cable.

[0010] This goal is attained by the features of claim 1.

[0011] In the invention, the contact element comprises a clearance whichmakes the seating fully accessible at three sides. The electrode supportreceived in the seating therefore is freely accessible at acircumferential angle of at least 180° from all sides. The plug isdesigned to be a clamping plug which is intrinsically retentive andpivotably engages the electrical contact zone of the electrode supportand may be pivoted by a substantially large angle up to 180° and evenmore about the axis of the electrode support. In the process, when theresectoscope is rotated, the cable suspended from the plug may behanging from it in swiveling manner, leaving the rotation unhampered.

[0012] The features of claim 2 are advantageous. They improve thereliability of clamping of the clamping plug because its groove assuresreliable retention on the electrode support against detachment.

[0013] The invention is shown in the drawings in illustrative andschematic manner.

[0014]FIG. 1 is a longitudinal section through a resectoscope of theinvention, and FIG. 2 is a section along line 2-2 of FIG. 1.

[0015] The resectoscope 1 shown in FIG. 1 comprises a stem tube 2affixed at its proximal end to a main block 3. In manner not shownherein, the stem tube 2 may be detachably affixed by conventionalcoupling element(s) to the main block 3. An external tube 4 encloses thestem tube 2 and also is affixed to the main block 3, againconventionally, using an omitted coupling element. The inside of thestem tube 2 serves in conventional manner as a feed duct of continuousirrigation and, as shown by FIG. 2, communicates with outside equipmentby a valve-fitted hookup 5 which can be connected to a hose. Anothersimilar hookup 6 for a further hose is connected to the annular gapbetween the stem tube 2 and the external tube 4 serving as the returnduct.

[0016] The two tubes 2, 4 are conventionally made of metal. The distalend of the stem tube 2 is conventionally electrically insulating, forinstance being in the form of a ceramic end piece 7.

[0017] An optics 8 which, in the shown assembled configuration, views byits distal objective 9 the surgical region before the ceramic end piece7 and proximally crosses the main block 3, runs inside the stem tube 2and parallel to the axis. Said optics 8 further runs through a guidetube 10 affixed in the main block 3 and terminates on the other side ofsaid main block's proximal end in an ocular 11 that optionally may bereplaced by a camera.

[0018] A slide block 13 is supported in axially displaceable manner bymeans of its guide borehole 12 on the guide tube 10. An end plate 14 isaffixed to the proximal end of the guide tube 10 and resiliently bracesthe opposite slide block 13 in this embodiment only by means of theconventional leaf spring 15. A thumb ring 16 is mounted on the end plate14, and a finger grip 17 is mounted on the slide block 13. Using onehand, the surgeon can seize by his thumb the thumb ring 16 and by hisindex finger the finger grip 17 and thereby axially displace the slideblock 13. Alternatively, in lieu of the “active” drive discussed above,a “passive” drive also may be used whereby the leaf spring 15 isconfigured between the slide block 13 and the main block 3 and theactuators 16, 17 also are configured at those components.

[0019] The shown resectoscope comprises an exchangeable, hf-loadedelectrode 18 which in its conventional prostate resection design is inthe form of a wire loop of which the plane is orthogonal to theresectoscope axial direction. The electrode 18 is supported by anelectrode support 19 in the form of an inner conductor wire 20 enclosedby an outer insulation. In conventional manner, the electrode support 19rests by a collar 21 in longitudinally displaceable manner on the optics8 and crosses the stem tube 2 as far as the main block 3. There itcrosses a sideways deflected transmission duct 22 fitted with an O ring23 or the like acting as a liquid seal and exits from said duct'sproximal mouth again parallel to the resectoscope axis but at a largerspacing as far as into receiving borehole 24 in the slide block 13.Alternatively, the seating borehole 24 may be replaced for instance by aproximally converging aperture, by sideways open slots or the like toseat the electrode support 19.

[0020] In its proximal end region, the electrode support 19 comprises anaffixation zone 25 which constitutes its end and which is made ofsufficient mechanical strength, for instance being solid metal, toreliably mechanically affix the electrode support in that zone. Brieflydistally from there, the electrode support 19 comprises a contact zone26 fitted with an externally electrically conducting outside surfacewhich is connected electrically with the conductor wire 20 of saidelectrode support.

[0021] Moreover the seating borehole 24, in the form of its proximal end27, comprises a limit stop for the electrode support 19, said electrodesupport being insertable into the resectoscope in the direction of theseating borehole 24 as far as said limit stop.

[0022] If, in the shown assembled position, the electrode support 19 hasbeen inserted into the seating borehole 24 of the slide block 13 all theway to the limit stop 27, then it shall be situated by its affixationzone 26 in a clearance 28 of the slide block 13, said contact zone 26then being freely externally accessible. In this position, saidelectrode support can be electrically connected by means of the shownclamping plug 29 at the end of an extension cable 30 running to anomitted hf generator.

[0023] The geometry of the clearance 28 is shown enlarged and in greaterdetail in FIG. 2. FIG. 2 shows that the clearance 28 entirely crossesthe slide block 13 transversely to the electrode support 19—shown by itscontact zone 26 in FIG.2—this crossing running from left to right inFIG. 2. In the transverse direction perpendicular thereto, that is, inFIG. 2 from bottom to top, the clearance extends from the underside ofthe slide block 13 to a height on the other side of the seatingborehole, that is beyond the contact zone resting therein, to a surface32 which is configured spaced away from the contact zone 26, that isfrom the seating borehole 24. As a result and as indicated in FIG. 2 bythe two dashed lines and by the circular arrow, the contact zone 26within the clearance 28 shall be accessible from all sides within anangle much larger than 180°. The remaining, shaded region of the slideblock 13 implements adequate mechanical coupling between the slideblock's components axially situated in front of and behind the clearance28 and it allows sliding guidance of the slide block 13 and its guideborehole 12.

[0024] The clamping plug 29 is shown in a simple embodiment appropriatefor the purposes herein. It comprises two jaws 31 each made of anelectrically conducting and mechanically resilient material and forsafety are externally fitted with an insulation 33. At least one of thejaws 31, but in this embodiment both, are fitted at their ends withchannels 34 whereby they reliably clamp the contact zone 26 and thiswith sufficient force of retention to preclude accidental removal of theplug 29 from said contact zone.

[0025] For the sake of simplicity, the drawing omits devices by means ofwhich the clamping jaws can be opened against their spring force. Forthat purpose the jaws 31 illustratively may be fitted at the plug 29with an omitted opening device. Instead of mounting the jaws inresilient manner, they also may be affixed to the plug 29 inarticulating manner for instance like tongs' arms, including anappropriate spring force to secure the clamping force.

[0026] An affixation element which in the present embodiment comprises atransverse borehole 31, that is present in the slide block 13 and thatillustratively and optionally is threaded on its inside allowingscrewing-in a tightening screw, is configured directly proximally of theclearance 28 in the region of the affixation zone 25 of the electrodesupport 19. Alternatively the affixation element may be of anotherdesign, for instance being fitted with a slider engaging a groove, or asnap-in element, or the like.

[0027] When the electrode support 19 is affixed in the slide block 13and is electrically connected in standard manner, then the entireelectrode support 19 together with its electrode 18 may belongitudinally displaced relative to the stem tube 2 by means of theabove described sliding motion of the slide block 13. By observingthrough the optics 8 and provided that hf is applied to the electrode18, ablating surgery with axial displacement may then be carried outwith said electrode.

[0028] In order to exchange the electrode 18, the clamping plug 29 isremoved and the affixation element (transverse borehole 31) is loosened.Thereupon the electrode support can be fully removed distally from theresectoscope 1. Vive-versa, a new electrode may be inserted in theproximal direction as far as the limit stop 27, and be mechanicallyaffixed and electrically contacted. The exchange of the invention allowsfirst mechanically affixing the electrode support 19 at the transverseborehole 31 and to test its appropriate mechanical performance by movingthe slide block 13 to-and-fro before electrical contact shall be madewith the clamping plug 29.

[0029] In the shown embodiment, the electrode support 19 bears anelectrode 18 in the form of a conventional resectoscope loop. The shownelectrode 18 however also may be replaced by electrodes exhibitingdifferent geometries, for instance being button, pin, roller or knifeelectrodes which when loaded with hf shall implement coagulation,vaporization or cutting.

[0030] Moreover bipolar electrodes may be used, where the electrodesupport 19 therefore shall bear the two electrodes to be connected tothe two output terminals of an hf source. In that case two conductorwires 20 must be used inside the insulating electrode support 19. Incorresponding manner, instead of the single contact zone 26 above, twocontact zones must be provided, electrical contacting of which forinstance may be implemented by means of a double plug. In this instancethe jaws 31 of the clamping plug may be constituted in each case of twoparallel resilient prongs.

[0031] In the shown embodiment, the limit stop relating to the insertionof the electrode support 19 is constituted by the end 27 of the seatingborehole 24. However a limit stop also may be fitted onto the clampingelement itself, for instance at the tightening screw which shall bescrewed into the threaded borehole 31. If the clamping elementillustratively were a slider engaging a groove in the affixation zone25, then a stop also may be fitted on that slider and would cooperateappropriately, for instance with a corresponding stop on the affixationzone 25.

1. A urological resectoscope (1) comprising an axially running stem tube(2) affixed at its proximal end to a main block (3), further a slideblock (13) axially displaceable relative to the main block (3) beingsupported proximally from said main block and including a seat (24),further an affixation element (31) and a clamping plug (29), anhf-loaded electrode (18), jointly with an electrode support (19) thatexhibits an externally insulated conductor wire (20), being axiallydisplaceable in supported manner beyond the distal end (7) of the stemtube (2), where, when the said resectoscope is in its assembled state,the electrode support (19) runs through the stem tube (2) and throughthe main block (3) as far as into the seat (24) where it can be affixedby means of the affixation element (31), the slide block (13) exhibitinga clearance (28) fully crossing it and running transversely to the seat(24), the clamping plug (29) engaging said clearance in order to set upelectrical connection with the electrode support (19) characterized inthat the clearance (28) runs transversely and perpendicularly to theseat (24) from the underside of the slide block (13) to a height (32) onthe other side of the seat (24) and in that the clamping plug (29) isdesigned to allow swiveling clamping action onto an electrical contactzone (26) of the electrode support (19).
 2. Resectoscope as claimed inclaim 1, characterized in that the clamping plug (29) comprises twocooperating clamping jaws (31), at least one jaw being fitted at itselectrical contact side with a groove running transversely to the jaw.